Designing & Building Hammerhead

Salty Pelican said:

Looking good, Xlantic! Thanks for sharing.

OC, Mako,

The JD 4540 is the main engine. The electrical engine will be back-up propulsion. Solar energy will provide enough electrical power for the house-banks ... and then some. The generator will serve as a back-up to the solar power generation AND serve as the back-up for the main engine, providing electricity to the electrical motor. Solar panels and generator electricity will be stored in a Lithium/ion battery pack that will power the electrical engine. Or the other way around, where the electric engine draws in power from the shaft/main engine and serves as the back-up to the generator.

Triple redundancy. And basically what in a car would be called a hybrid system, that also helps to manoever the ship in-harbor on electric power only (electrical motor for propulsion forward or backward and electric bow and stern thrusters).

Regards, Edwin.

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Are you referring to a JD 4045?

I installed the same motor in my boat. You probably don't need it with all the solar and a generator, but I installed a second high output alternator with an external regulator on my 4045. A few hours on cruising charges my house bank. If you're interested, there is an album of pictures on my forum profile page showing the second alternator.

Ted

Thanks!

I am thinking of taking the alternators off completely, since they are a relatively inefficient way to produce electric power. As I understand it. And there is enough solar power (understatement) and a generator and we can use the electric engine to create electrical power as well.

Regards, Edwin.

Salty Pelican said:

Thanks!

I am thinking of taking the alternators off completely, since they are a relatively inefficient way to produce electric power. As I understand it. And there is enough solar power (understatement) and a generator and we can use the electric engine to create electrical power as well.

Regards, Edwin.

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Not sure about yours, but mine uses the original alternator as the serpentine belt tensioner.

The alternator is also more efficient at battery charging than a generator powering a battery charger.

Ted

Xlantic said:

Edwin, I also built a solar-panel roof above the fly-bridge. I added a front "visor" with a similar angular look to the front of the fly-bridge and house which also adds strength and rigidity to the roof.

I have also built but not yet installed a mirror visor or hood for the aft end.

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That’s a good idea I like that wish ,I wish I would’ve thought of it ,I just built a top for my cockpit,That one very nice

Hmmm ... from a discussion with the shipyard, where our current boat is under maintenance, I understood that alternator generated electricity is very inefficient. That it takes about twice the fuel for the same number of kWh's, when compared to a generator.

Regards, Edwin.

Salty Pelican said:

Hmmm ... from a discussion with the shipyard, where our current boat is under maintenance, I understood that alternator generated electricity is very inefficient. That it takes about twice the fuel for the same number of kWh's, when compared to a generator.

Regards, Edwin.

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My 220 amp alternator generates about 3 KW at .3 GPH (the JD 4045 displays real time fuel consumption). My 8 KW generator consumes 1 GPH at full load.

Taking the 120 VAC power from the generator and running through a battery charger has a further significant inefficiency in the power conversion.

While solar would be your obvious first choice, using a generator solely to charge batteries would also have a significant infrastructure cost (hours on the generator) as opposed to utilizing an already running main engine.

I think it would be a good idea for you to do your own research on the efficiency difference between the alternator and generator / battery charger.

Ted

Thanks OC, I will dive in deeper!

Regards, Edwin.

Salty Pelican said:

Hmmm ... from a discussion with the shipyard, where our current boat is under maintenance, I understood that alternator generated electricity is very inefficient. That it takes about twice the fuel for the same number of kWh's, when compared to a generator.

Regards, Edwin.

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That's generally correct. I did a semi-scientific study of it on my blog a number of years ago.


Adventures of Tanglewood: Engine Alternator or Generator: Which is More Efficient?


In a nut shell, an alternator is most efficient at lower power outputs, and less efficient at higher power outputs, mostly due to high current I2R losses in the stator windings. A generator is the opposite, being less efficient at low output since you still have all the parasitic loads of the engine running, and more efficient at higher outputs. There is a cross over somewhere in the lower middle output range. I found that for low power loads, the alternator was better. But for any significant power loads, it was better to run the generator.

Your Blog post on generator versus alternator was an interesting read. The one take away from your Blog worth highlighting (for this discussion) is that for charging batteries, the alternator is superior or about equal depending on the total AC load on the generator when including the loss on the battery charger.

Ted

Great info, gentlemen, thanks for sharing.

Now, if we consider that we have enough solar to power the boat's electrical needs, that means that the generator primarily functions as a back-up power source, as explained above.

In this case, wouldn't getting rid of the alternator actually save fuel, since it is always on and does consume diesel?

Regards, Edwin.

Salty Pelican said:

Great info, gentlemen, thanks for sharing.

Now, if we consider that we have enough solar to power the boat's electrical needs, that means that the generator primarily functions as a back-up power source, as explained above.

In this case, wouldn't getting rid of the alternator actually save fuel, since it is always on and does consume diesel?

Regards, Edwin.

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It only consumes fuel if it's generating power.

Salty Pelican said:

Great info, gentlemen, thanks for sharing.

Now, if we consider that we have enough solar to power the boat's electrical needs, that means that the generator primarily functions as a back-up power source, as explained above.

In this case, wouldn't getting rid of the alternator actually save fuel, since it is always on and does consume diesel?

Regards, Edwin.

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As Twistedtree indicated, almost zero fuel consumption when not in use.

Also, I preferred to have a separate battery only for the engine. Regardless of what else fails, I want everything associated with the engine to run off that battery and have it start. It takes almost nothing to start a JD 4045. In no time the battery will be recharged and the 12 VDC power required to keep the engine is very small, so very little fuel used to make 12 VDC. There's a lot to be said for electrical isolation on a single engine boat.

On my boat I added a battery switch that ties the engine battery to the house battery bank. If the engine battery fails, I can connect the batteries to start the engine.

Ted

MV,

I thought it was on all the time. It is on Salty Pelican. Okay, I need to do more research, so much becomes clear.

OC,

Yeah, that makes perfect sense!

Thanks again!

Regards, Edwin.

MV = TwistedTree.

I would keep my alternator, it will produce all the power you need while running from the A to B destination. A smart regulator is as well a must. In case you plan high latitude cruising keep in your mind that low pressure systems come in like freight trains, almost every 3 days, which means plenty of cloud cover. Solar panel will not be very effective than. On the point of wind generator in case this subject comes up, we had to shut our wind generator down, because the winds blow there in general between 25 and 50 knots,period. We hat to use the 6 KW diesel generator in the morning and in the evening for a hour and so to charge up the batteries to get us over the day. The hooked up 150 amp smart charger of our 3 kw inverter/charger did the work then. Get the "Windy" app and check your future cruising grounds. The sun might not be shining there all the times. Best regards, Benno

As it goes for battery banks, the propulsion diesel should have it own "starter" battery which it can chair it with the diesel generator as well. The bow thruster in case it is not hydraulic driven needs a "starter" battery too for the required power burst to be effective. The rest of power user require "storage battery" bank. These batteries are of slightly different manufactured technic. Regards, Benno

I agree!

So ... we tested/simulated various stabilizer fin configurations and the results are very good. About 90% damping is achieved at top speed and at our intended 10 knot cruising speed.

Regards, Edwin.

Blue is the non-stabilized boat state. As I understand, it is how the boat rolls without the fins working. Given a certain wave input. Orange is with the fins active. 5, 10, 15 degrees roles and more are easily brought back to 1 or 2 degrees role movements.

Regards, Edwin.

@Benno, obviously there are many ways to setup battery combinations.

I prefer to connect main engine starter to the house bank, then have the generator on its own battery, which can practically be a motorcycle battery. That provides important redundancy.

As the OP is likely going with lithiums, the house bank can be placed forward of the engine room and have short enough wires to power the windlass and thruster as well.

The fewer batteries the better.

Yes, Li-Ion batteries it will be.

Regards, Edwin.

@Mako, you are correct as the saying "Every Road leads to Rome" the use to say. The temperature in the engine room is not friendly for the location of battery banks. The engine starter bank can be placed very low and close to the aluminum plating where hull meets the keel to to be able to harvest the kool-skin effect. General the generator is close by and without long and heavy gauge cable run can be hooked to the same bank. The battery house bank I would mount close to inverter, isolation transformer, 12 vdc or 24 vdc master panel and the ac panel to keep wire and cable gauges manageable and locate it outside of the engine room. Edwin seems to build the new boat in aluminum, which is a super boat building material and has to consider an isolated ground in the 12vdc or 24vdc system and very important the ac shore power. The engine wiring needs to be isolated ground including the alternator. This is a another can of worms . You are right in fewer batteries are better and lithium is the way to go and including all the weight saving beside the use of most all the storage capacity.

Thinking about water makers ...

I feel a low pressure pump system with energy recovery might be the way to go. It costs only about 4 Watt to make a liter of water (16 Watt to the gallon) and you don't need to run the generator for it.

We are looking at Spectra (by Kathadyn) and at Schenker. Does anyone have any info or experience to share?

On how they perform, the costs, etc?

Much appreciated!

Regards, Edwin & Veronika.

Honestly I've never been too big a fan of aluminum especially for building a heavy trawler. But lately I'm changing my tune. Today I priced A36 steel plate at $2.60 per pound whereas I used to be able to source it for $0.60 per pound. Aluminum plate is hovering around $3.60 per pound. Petroleum products are through the roof now as well (go price PVC pipe at Home Depot) so fiberglass costs are up also.

It would seem that AL would be a practical and cost-effective building material these days for a new construction, as would wood if someone were so inclined.

If you build a trawler out of aluminium, it will be less heavy, Mako.

Regards, Edwin.

Experiences with water makers, anyone?

Regards, Edwin.

Experience of a good water maker
Edwin, let me tell you I went through the same thinking process you have while outfitting our DD41. The problem a 12VDC or 24VDC water maker has is they are extremely expensive to purchase and they have very little output per hour. Filters, parts and supplies are costly for them. It takes them almost a day to replace the liter of water used by you and Veronika.
We ended up purchasing the Offshore Marine Lab Sea Quencher, a 800 GPD modular water maker, which would make in 2 hours 66 gallon of good and clean water. This is 250-liter water in 2 hours. The same company that manufactures the “Village Marine TLM-800” made our Sea Quencher 800. The cost of that unit is a little under $7000 US. In the eight years on board living we never had a problem. Marlene had a “Splendide” washing machine on board to help her with the laundry and we could take showers galore to wash the salt off the skin and out of our hair. Many times I rinsed the boat down with fresh water. Look at the picture of our water maker and at Marlene’s U-shaped galley at Marlene and Benno's Odysseys on Land and Water Just click the link in the right-hand menu under the DD41 write-up “Interior Pictures of Diesel Duck”. This is more food for thought!
Best Regards, Benno

Liquid Management HQ!

We had a great meeting, last Friday, with our naval architect and the interior designer. We discussed various details of the boat for the better part of 5 (!) hours, making decisions as we went along.

Wanna see our boat head quarters? Here are a few pics!

Regards, Edwin & Veronika.

Benno said:

... The problem a 12VDC or 24VDC water maker has is they are extremely expensive to purchase and they have very little output per hour. Filters, parts and supplies are costly for them. ...

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Water makers are one of these boat things that no matter what you choose, it is both right and wrong.

DC units do not make as much water per hour compared to AC systems but they do not require a generator or inverter to work and they seem to be more money.

AC units provide more water per hour but require AC power and the complexity that is needed to provide AC on a boat.

Take your pick and don't look back.

If *** I *** had to pick a water maker today, I would pick one of the AC units from this site, https://www.cruiserowaterandpower.com/. One of the attractions for Rich's system is that he is using parts that should be easy to find in most places in the world and is not using proprietary filters and such.

Rich does have DC versions of his water maker.

He is also selling Schenker units now which is interesting.

Later,
Dan

"using parts that should be easy to find in most places in the world"

I think that if the intention were worldwide cruising and if one were handy (you'd better be!) then it might be best to assembly your own. A dead simple "dumb" unit without microprocessors. Carry spares of everything. Not just about saving money, but saving hassle also.

I think about that very colorful captain from that Discovery series who sailed his 100ft ferro boat through the NW passage. They showed clips of him repairing his obviously homebuilt RO maker in the middle of the arctic.